4-Chloro-3-sulfamoylbenzoic acid is the major metabolite of tripamide (N-(4-aza-endo-tricyclo[5. 2. 1. 0(2,6))]-decan-4-yl)-4-chloro-3-sulfamoylbenzamide), new antihypertensive agent. It is present as impurity in clopamide tablets and has been quantitated by chromatographic-densitometric method.